Shaft rods for weaving shafts are often created from light-metal profiles on which a steel heddle support rail is held. The heddle support rails are conventionally secured to the light-metal profile by a plurality of rivets that extend through the heddle support rail and a corresponding extension of the light-metal profile, thereby holding the heddle support rail in place. This securing system is limited. Care must be taken to prevent the shaft rods from being subjected to undesired bending during the riveting process, because otherwise the heddle play along the shaft rod will become non-uniform. It has also been seen that cracks often form in the region of the rivet bores, particularly at high operating speeds, and steel rivets are sheared off. The use of thicker steel rivets does not solve this problem, because they weaken the light-metal profiles to an unacceptable degree.
German printed Patent Application DE 39 37 657 A1 discloses a shaft rod for securing heddle support rails without rivets. The shaft rod has a wall-like, flat extension with two narrow, parallel ribs. The ribs define a slot-like receiving chamber between themselves. The associated heddle support rail has on its rear side a narrow retaining rib that is to be pushed into the receiving chamber. The rib has a certain amount of excess material, so it is seated in a press fit between the spread tabs or ribs of the retaining segment.
Forces exerted on the heddle support rail act as bending forces on the retaining ribs. At high operating speeds, the seating of the heddle support rail poses a problem.
German Patent DE 33 23 224 C2 discloses a shaft rod that is formed from a light-metal profile. To some extent, the rod replaces the conventional heddle support rail. The light-metal profile has a strip-like segment that is provided on its top side and underside with a U-shaped protective profile. Consequently, the precision of the heddle play is a function of the precision of the securing of the two U-profiles relative to one another. Many users therefore prefer conventional heddle support rails made from a suitable steel profile.
In view of the above problems, it is the object of the invention to create a shaft rod that is suitable for high operating speeds.